Machine for sterilization by compression



June 1, 1 937- DQDGE 2,082,445

COMPRESSION NE FOR STE F lled Sept. 19, 1935 INVENTOR. 4 AD/EL X DODGE Patented June 1, i937 UNITED STATES PATENT orrica Adiel Y. Dodge, South Bend, Ind. Application September 19, 1935, Serial No. 41,224

15 Claims.

This invention relates to sterilizing machines and more particularly to machines for continuous mechanical sterilization of fluids such as liquids.

One machine, according to the invention, for the continuous and rapid treatment of fluids or semi-fluids, such as fruit juices, milk, serums or the like, may comprise a resiliently-expansible pressure chamber, means such as a plunger or piston for producing a cycle of high and low 1 pressure within the chamber, valves for confining a charge of the fluid in the chamber while under high pressure and permitting its escape while under low pressure, suitable means in the form of a pump for, displacing the processed charge and injecting a new charge and suitable actuating and synchronizing connections in the form of gears, cams, etc. where y the process of treating the fluid is carried out insequence and in repeated cycles under the influence of a single motive source and without the necessity of continuous manual control.

One important feature of the invention relates to the recovery of most of the energy of compression, which heretofore has been wasted by dis charging the treated liquid, while at high pressure through restricted orifices or spring pressed valves. This novel feature of my invention is of great importance as it substantially reduces the amount of energy required to treat a given quan- 30 tity of fluid.

Another feature of the invention concerns the accurate controllability of the pressure obtained from which a greater uniformity of treatment results.

I prefer to accomplish both of the above results by providing in one end of the pressure chamber a spring-held plunger which is adapted to be pushed out against the tension of the springs by the fluid under pressure as a driven plunger or 0 piston advances into the pressure chamber. The energy imparted by the motive source is stored up partly in the stretched spring and partly in the compressed fluid. All of this energy, except that lost in friction, is returned to the" motive source on the return stroke of the piston and may be stored up in a flywheel to be used in the succeeding cycle or imparted to another cylinder through a crankshaft if multiple cylinders are employed.

Other features of the invention relate to the injection of a gaseous or liquid reagent such as CO2 into the fluid prior to its being subjected to high pressure and to passing an electric current thru the liquid while under high pTessure.

A further novel phase of the invention resides 5 in provisions for creating a high pressure followed by a subnormal pressure. I prefer to accomplish this by timing the valves in the pressure chamber to close when the pressure piston hasmoved part way into the cylinder on the pressure stroke and to open when the piston has moved farther outwardly on the relief stroke.

Still another feature of the invention resides in providing means whereby a given portion of liquid may be subjected to two or more cycles of pressure before being displaced by the next portion to be treated.

The above and other objects and features of the invention including various novel combinations of parts and desirable particular constructions will be apparent from the following description of the illustrative embodiment shown in the accompanying drawing, in which:

Figure 1 is a plan view partly in section of a machine embodying the invention;

Figure 2 is a detail of the pump operating cam;

Figure 3 is a detail of one of the valve operating cams; and

Figure 4 is a diagram illustrating one desirable cycle of operation of the machine.

In the machine illustrated there is a motor Ill driving a crankshaft [4 through a suitable speed reduction gearing I2, the crankshaft l4 being pro-7 vlded with a flywheel iii, a crank l8 and a camshaft drive gear 20. A suitable linkage 22 journaled on the crank l8 converts the rotary motion of the crank into reciprocatory motion of a piston or plunger 24 of small diameter which projects into a cylinder 26 in a body member 28.

Member 28 is provided with an enlarged cylindrical pressure chamber 30 communicating directly at one end with the cylinder 26 and having at that end an inlet port 32 and at the other end an outlet port 34 both of which are controlled by inwardly opening poppet valves 36 and 38 respectlvely.

The end of the pressure chamber opposite the cylinder 26 is closed by a movable piston 40 shown integral with a spring yoke 42 to which are attached a. plurality of large tension springs 44. The other ends of the springs 44 are fastened to a similar yoke 46 which may be attached in any suitable manner (not shown) to the member 28 so as to be adjustable to increase or decrease the tension of the springs.

Communicating with the inlet port 32 by means of a conduit t8 and a ball check valve 50 is a feed pump comprising a cylinder 52 and a piston 5 Fluid enters this pump through a pipe 55, a strainer 56 and a non-return valve 58. A spring 60 acts on the piston to move it outwardly and simultaneously exerts sealing pressure on a packing gland 62. The piston is provided at its outer end with a roller 64 in contact with a cam 66 (see Figure 2) adapted to move it inwardly.

The cam 66 and two valve operating cams 12 (see Figure 3) are mounted on a camshaft 68 rotatably supported in suitable bearings and driven by a gear 10 meshing with and having the same number of teeth as the gear 20. The two cams T2 are identical and are disposed in the same angular relation so as to actuate the valves 36 and 38 simultaneously through pushrods 14 and rocker bell cranks 16. Valve springs 18 are provided to hold the valves in closed position.

A needle valve 80 admits a metered amount of a suitable liquid or gaseous reagent such, for example, as CO2, to the conduit 48 from a tube 32 connected to any suitable source of supply.

The checkvalve 50 serves to prevent this reagent from being drawn into the feed pump.

Two electrodes 83 are suitably mounted in insulating sleeves at the extreme ends of the chamber 30 and have external terminals to which are attached leads 84 from a source of electric power. I

The current applied may be of such character as to electrocute the microorganisms, or alternatively of such character as to create a substantial heating eifect with consequent sterilization or a combination of both. The presence of such a substance as CO2 in solution in any liquid containing a substantial quantity of water will, because of its acid character, materially increase the conductivity of the liquid and the effectiveness of the electric current.

Referring more particularly to Figures 2, 3 and 4, in which the arrows indicate the direction of rotation of the pump cam, valve cams and crank, respectively, the operation of the illustrated machine is as follows.

Beginning at point A, the crank I8 is 15 above outer dead center, cam 66 is just beginning to move the piston 54 inwardly and cams 12 are beginning to open the valves 36 and 38. The liquid to be treated flows from the cylinder 52 through the check valve 50 into conduit 48 (where, if desired, it is mixed with the reagent admitted by the needle valve 80) and past valve 36 to the pressure chamber 30 forcing the liquid which previously occupied the pressure chamber out past the valve 38 through the outlet' port 34 to any suitable reservoir (not shown) or other point of use.

When the crank reaches point B 45 beyond outer dead center the piston 54 has moved to its extreme inward point and the valves 36 and 38 are closed. The piston 54 should be so proportioned to the chamber 30 that at the end of its stroke most but not all of the previously treated liquid in the pressure chamber has been displaced. Overlapping the charges in this manner insures that no liquid escapes treatment. Continued rotation of the cam 66 permits the spring 60 to force the piston outwardly and draw in a new charge from the liquid reservoir in preparation for the next cycle.

Rotation of the crank beyond B moves the plunger 24 inwardly on its compression stroke until at point C it reaches inner dead center. The liquid being largely incompressible forces the plunger 40 outwardly against the tension of the springs 44 and is thus subjected to a high pressure. Since the pressure in the pressure chamber is limited by the tension of the dead center.

springs 44 which is constant from cycle to cycle, all of the liquid will be subjected to the same pressure without any necessity for accurate calibration of the charge admitted.

The energy imparted to the liquid by the piston 24 is stored in the springs and compressed liquid and as the piston moves outwardly this energy is returned to the crankshaft, accelerating it and thus being stored in the flywheel in the form of kinetic energy. On each succeeding cycle this energy is again imparted to the liquid and springs and again returned so that it is apparent that once the mechanism has been brought up to its operating speed the only energy drawn from the motor is that lost in mechanical and fluid friction and that used in the low pressure pumping operation. This represents a very substantial saving over the energy required to pump liquid at high pressure through an orifice or spring pressed valve.

Returning to the illustrative cycle it will be seen that when the crank i8 reaches point D the piston 24 occupies the same position it did when the valves closed; plunger 40 has returned to its normal position with yoke 42 abutting member 28; and further withdrawal of the piston until the crank reaches the valve opening position A subjects the liquid to a subnormal pressure, it being understood that valve springs 18 exert such a pressure as to hold the valves closed during this period.

If a subnormal pressure is not desired the camshaft drive gears may be unmeshed and shifted so that the valves open at 30 above bottom dead center and close 30 below bottom By appropriate shifting of these gears any practical degree of sub-pressure may be obtained.

The machine may easily be modified to subject the liquid to two or more successive pressure cycles before discharging it by replacing gears Ill and 20 by two gears having e. g. a two to one ratio whereby one valve and pump operation occurs during two crank revolutions.

Any desired range of pressure can be obtained by adjusting the yoke 46 and/or substituting springs 44 having various rates. Once any desired pressure is obtained it is apparent that no undesirable variations can occur while the machine is in operation.

One desirable process which may be carried out by the use of my novel machine is disclosed and claimed in my copending application Serial No. 622,232 filed July 13, 1932.

While one particular embodiment of my invention has been illustrated and described, it is not my intention to limit it to this embodiment or otherwise than by the terms of the appended claims.

What is claimed is:

1. In a mechanism for treating liquid a resiliently-expansible chamber, means for alternately compressing and expanding liquid therein, and means for recovering part of the energy of compression during the expansion stroke.

2. In a mechanism for treating liquid a resiliently-expansible chamber, means for alternately compressing and expanding liquid therein. means for recovering part of the energy of compression during the expansion stroke, and means for circulating fluid under pressure into and out of the compression chamber.

3. A device for treating liquids comprising a cylinder having a spring held plunger in one end and a reciprocating piston in the other end, in

combination with valve means for confining liquid in said cylinder while the piston is moving toward the plunger on a compression stroke and which valve means is opened near the end of the stroke of said piston away from the plunger.

4. A device for treating liquids comprising a compressor device, inlet and outlet valves therefor to control inlet of liquid thereto and outlet of liquid therefrom, and means for holding both valves closed during the major part of both compression and relief strckes of said device and for opening both valves near the end of the relief stroke.

5. An automatic device for treating liquids comprising a compressor device, inlet and outlet valves therefor to control inlet of liquid thereto and outlet of liquid therefrom, means for holding both valves closed during the major part of both compression and relief strokes of said device and for opening both valves near the end of the relief stroke, and means for injecting a new charge into said device when the valves are open.

6. A machine for sterilizing liquid by compression comprising a compression chamber, a plunger operable in said chamber, and means for aerating the liquid.

'7. A machine for sterilizing liquid comprising means having a plurality of resilient compression chambers, a plunger for each compression chamber, means for' reciprocating the plungers in the compression chambers, valves controlling inlet and outlet of fluid to the chambers, means to open the valves at the outer ends of the plunger strokes, and means for injecting a gas into the liquid.

8. A machine for sterilizing liquid comprising means having a plurality of resilient compression chambers, a plunger for each compression chamber, means for reciprocating the plungers in the compression chambers, valves controlling inlet and outlet of fiuid to the chambers, means to open the valves at the outer ends of the plunger strokes and means for passing an electric current through the liquid.

9. A device for treating liquids comprising means for subjecting a portion of liquid to a high pressure, means for passing an electric current through the liquid while it is under pressure, means for injecting a reagent into the liquid, and

means for delivering a portion of mixed liquid and reagent to the pressure means.

10. A machine for sterilizing liquids comprising means for subjecting a charge of liquid to a high and low pressure, pump means to replace the liquid charge while at low pressure and means actuating and synchronizing the above named means. 11. A machine for treating liquids comprising means for subjecting a charge of liquid to a high and low pressure, valve means for confining the liquid while under high pressure and permitting its escape while at low pressure feed means to force a new charge of liquid into the first named means and means actuating and synchronizing both the above named means.

12-. A continuously operating device for sterilizing liquid comprising a resilient, pressure chamber having a reciprocating plunger, normally closed valve means for controlling inlet and ex-, haust of liquid to the pressure chamber, pump "means for forcing a new charge into the chamber,

acam shaft geared to the plunger, cams on said shaft arranged to open the valves near the end of the return stroke of the plunger and close them during the pressure stroke, and another cam driving said pump means operative while the valves are open.

1 3. A machine for sterilizing liquid comprising a pressure cylinder, a piston reciprocable in said cylinder, power means to operate'the piston, resilient means associated with the cylinder to limit the pressure in the cylinder, and valves to control 4 the inlet and exhaust of liquid to and from the cylinder, said valves being operated by the power means.

14. A machine for sterilizing liquid comprising means for adding a gas to the liquid and means for passing an electric current through the liquid and means for compressing the mixture of gas and liquid simultaneously with the passage of electric current therethrough.

15. A machine for sterilizing liquid comprising means for adding CO2 to the liquid and means for passing an electric current through the liquid and means for compressing the mixture of gas and liquid simultaneously with the passage of electric current therethrough.

ADIEL Y. DODGE. 

